The electrical system (100) includes: —a capacitor (C); —an electrical power supply device (102); —an electrical power receiving device (104); —a current-consuming electrical circuit (108) designed to consume a current (i) entering via a first interface terminal (B.sub.A) and exiting via a second interface terminal (B.sub.B). The electrical system (100) being designed such that the current-consuming electrical circuit (108) consumes the discharge current (i) when the electrical power supply device (102) is connected to the terminals of the capacitor (C). The current-consuming electrical circuit (108) includes a transistor (Q1) arranged such that the consumed current (i) enters via a current input terminal (C1) of the transistor (Q1) and exits via a current output terminal (E1) of the transistor (Q1), and in that the current output terminal (E1) is connected to a control terminal (B1) of the transistor (Q1) in order to stabilize the transistor (Q1).

In an installation including a stored energy source and an electric motor which can be fed by an inverter, and a method for operating an installation, the stored energy source forms an electrical series circuit with a first fuse and further fuse(s). A controllable contact, e.g., a switch, a contactor, etc., is connected in parallel to the further fuse, or a respective controllable contact, e.g., a switch, a contactor, etc., is connected in parallel to each of the further fuses. The series circuit feeds the DC-voltage-side connection of the inverter, and a device for detecting the voltage applied to the series circuit is connected to control electronics which generate a control signal for the contact or control signals for the controllable contacts. For example, the respective contact is opened when the voltage falls below a respective voltage threshold.

A control device for an MMC is disclosed. The control device for an MMC including a plurality of converter arms that include a plurality of sub-modules connected in series and that are connected to a DC link includes: an arm controller, which detects the arm current of a converter arm so as to determine whether a DC failure has occurred, and, if it is determined that the DC failure has occurred, transmits a bypass control signal for protecting a sub-module and notifies of the DC failure; a sub-module controller for controlling the sub-module so as to bypass a DC failure current according to the bypass control signal received from the arm controller; and a main controller, which detects, in real-time, the arm current of the converter arm and a voltage (DC link voltage) of the DC link, determines whether the DC failure is a temporary DC failure or a permanent DC failure on the basis of the detected arm current and DC link voltage if the occurrence of the DC failure is notified by the arm controller, and transmits, to the arm controller, a normal operation control signal for normal operation of the sub-module or a bypass control signal for bypassing of the DC failure current.

Exemplary electrical disconnects may include a housing defining a first access at a first end of the housing and a second access at a second end of the housing. The second access may extend vertically along a height of the housing beyond a vertical location of the first access. The electrical disconnects may include a busbar characterized by a first segment and a second segment. The first segment and the second segment may be coupled at a break section of the busbar. The first segment of the busbar may extend through the first access of the housing. The second segment of the busbar may extend through the second access of the housing. The electrical disconnects may include a pyrotechnic initiator disposed within the housing. The electrical disconnects may include a blade laterally aligned with the break section of the busbar. The electrical disconnects may include a plunger within which the blade is seated.

An electrical system forming part of a solar power plant is described. The electrical system includes a plurality of photovoltaic (PV) panels, a power converter, and a controller. In response to a detected electric arc on the DC side of the power converter, the controller is configured to enable a short circuit state of the power converter by controlling semiconductor switches of the power converter (e.g., turning on some or all of the semiconductor switches) to create a short circuit between DC input terminals of the power converter. The short circuit path though the power converter will extinguish the detected electric arc in the connected DC circuit.

An electrical conversion system includes an inverter arranged according to a multilevel type topology with k arms and a command device for cut-off against an electrical overload, connected to a set of first intermediate lines to measure a first intermediate continuous voltage. The cut-off command device is configured to determine a fault by detecting if the first measured intermediate continuous voltage is outside of a nominal voltage variation range [Vmax1, Vmin1] of the first intermediate voltage and to transmit a generalised opening command signal for an opening of the electronic commutation switches of each arm when the fault is determined.

A threshold detection system can be configured to monitor a location (e.g., a DC link) for overcurrent. The threshold detection system can be configured to generate a pulse width modulated signal with a duty cycle that is proportional to current through the DC link. The threshold detection system can be configured to determine whether the duty cycle exceeds a selected threshold.

A power converting system includes a power converting device, a protection device, and a charging device. The power converting device is coupled to a first and a second power source. The protection device is coupled to the power converting device, a load, and a grid, and switches electrical connections among the power converting device, the load, and the grid. The charging device is coupled to the power converting device and a third power source. The power converting device charges the third power source through the charging device, or receives electricity through the charging device. Select at least one power source of the first power source, the second power source, the third power source and the grid to provide electricity to the load according to multiple preset modes.

A system for protecting a vehicle inverter from overvoltage includes a first inverter having switching elements and converting energy from an energy storage device into AC power. A first motor is driven by receiving the converted AC power. A second inverter is connected in parallel with the first inverter, includes a switching elements, and converts energy from the energy storage device into AC power. A second motor is driven by receiving the converted AC power. A first capacitor is connected in parallel between the first inverter and the energy storage device and stores electric energy of the first motor during regenerative braking. A controller turns off a relay connecting the energy storage device and the motor when a voltage of the first capacitor is equal to or greater than a predetermined voltage and operates the switching elements in the inverters in response to first and second current commands.

In a multilayer printed circuit board (circuit board 20) having an inverter (switching elements 22) mounted thereto, only a second wiring pattern P2 arranged downstream of a semiconductor relays 24 and able to shut off an electric power supply and a third wiring pattern P3 arranged upstream of a shunt resistor 27 and able to detect an overcurrent are placed in adjacent layers in a manner to face each other, and thus, even if the mutually facing portions (laminated portion) of the these two wiring patterns P2 and P3 are subjected to short circuit, an overcurrent caused by the short circuit can be detected by the shunt resistor 27 and the electric power supply to the switching elements 22 can be shut off by the switching elements 22, so that overheating at the second and third wiring patterns P2 and P3 can be avoided.